“His Holiness is a spiritual leader,” she said. “I hear unfortunate things that the spiritual leader of this capital is loathe to upset China and meet spiritual leader to spiritual leader.

“What does that say? Where is conviction? Where is truth? Where is morality, when the spiritual leader in Rome bows in one way or another to economic pressure from China? That is another kind of warfare.”

The controversy comes as the Vatican attempts to improve its fraught relations with China.

The church sent a general message of greeting to the Nobel congress.

Father Giulio Albanese, Pope Francis’ spokesman, said: “His Holiness is deeply grateful for the commitment of the summit participants to promoting peace and fraternity among peoples and for their efforts in finding solutions to the conflicts of our day.”

Away from the congress, the Pope celebrated an evening mass at the Vatican to mark a feast known as the day of Our Lady of Guadalupe.